I'm considering pushing an update to F-9 since v3.5+ is so much faster
than previous releases - and it impacts boot time, but I have to admit
that I was more concerned about F10 and rawhide until now.

Oh, there's a slight issue with the handling of modules.order still for
the binary tries in newer module-init-tools. This might manifest in a
switch of e.g. module used in initrd for storage devices with multiple
modaliases.

So...one question...
We now have binary versions of files like "modules.dep", "modules.alias"
and "modules.symbols". These end in ".bin" and *augment* but do not
replace the textual versions of these files. If we find the binary
files, we are *much* faster at loading modules - boot overhead is e.g.
under one second.
But we need to be able to make changes to these binary files in order to
add ordering support, and also just for the future. Our plan is to
freeze the old text file format (the "last" change will be the one made
recently in which modules.dep can now have relative paths to save space)
and to fallback to it whenever the binary format changes and modprobe
finds older binary files.
This works fine, but means that, if we upgrade module-init-tools and
there is a binary format change, then the system will be "slow" booting
before depmod has been re-run again. I'm thinking about just doing a
"depmod -a" on upgrade in such cases in the future...is there a problem
with that idea?
Jon.

Imho in case of an update of module-init-tools that sounds absolutely
reasonable. Users are much more likely to reboot their machines then get
updates for module-init-tools, so the little overhead introduced with
running depmod -a during an update should in general be significantly
lower than the gains in subsequent bootups.